Fix #1546. New feature to copy the material of the active object to selected objects.

src/blenderbim/blenderbim/bim/module/classification/ui.py

@@ -41,7 +41,7 @@ class BIM_PT_classifications(Panel):
         row = self.layout.row(align=True)
         row.prop(self.props.classification_attributes.get("Name"), "string_value", text="", icon="ASSET_MANAGER")
         row.operator("bim.edit_classification", text="", icon="CHECKMARK")
-        row.operator("bim.disable_editing_classification", text="", icon="X")
+        row.operator("bim.disable_editing_classification", text="", icon="CANCEL")
 
         for attribute in self.props.classification_attributes:
             if attribute.name == "Name":

src/blenderbim/blenderbim/bim/module/material/__init__.py

@@ -2,6 +2,7 @@ import bpy
 from . import ui, prop, operator
 
 classes = (
+    operator.CopyMaterial,
     operator.AddMaterial,
     operator.RemoveMaterial,
     operator.AssignMaterial,

src/blenderbim/blenderbim/bim/module/material/operator.py

@@ -754,3 +754,45 @@ class EditMaterialSetItem(bpy.types.Operator):
 
         bpy.ops.bim.disable_editing_material_set_item(obj=obj.name)
         return {"FINISHED"}
+
+
+class CopyMaterial(bpy.types.Operator):
+    bl_idname = "bim.copy_material"
+    bl_label = "Copy Material"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def execute(self, context):
+        return IfcStore.execute_ifc_operator(self, context)
+
+    def _execute(self, context):
+        self.file = IfcStore.get_file()
+        material = ifcopenshell.util.element.get_material(
+            self.file.by_id(context.active_object.BIMObjectProperties.ifc_definition_id)
+        )
+        for obj in context.selected_objects:
+            if obj == context.active_object:
+                continue
+            if not obj.BIMObjectProperties.ifc_definition_id:
+                continue
+            ifcopenshell.api.run(
+                "material.copy_material",
+                self.file,
+                **{
+                    "material": material,
+                    "element": self.file.by_id(obj.BIMObjectProperties.ifc_definition_id),
+                },
+            )
+            Data.load(self.file, obj.BIMObjectProperties.ifc_definition_id)
+            self.set_default_material(obj, material)
+        return {"FINISHED"}
+
+    def set_default_material(self, obj, material):
+        object_material_ids = [
+            om.BIMObjectProperties.ifc_definition_id
+            for om in obj.data.materials
+            if om is not None and om.BIMObjectProperties.ifc_definition_id
+        ]
+
+        if material.id() in object_material_ids:
+            return
+        obj.data.materials.append(IfcStore.get_element(material.id()))

src/blenderbim/blenderbim/bim/module/material/ui.py

@@ -118,6 +118,8 @@ class BIM_PT_object_material(Panel):
                 op.material_set_usage = self.product_data["id"]
             row.operator("bim.disable_editing_assigned_material", icon="CANCEL", text="")
         else:
+            if self.product_data["type"] == "IfcMaterial":
+                row.operator("bim.copy_material", icon="COPYDOWN", text="")
             row.operator("bim.enable_editing_assigned_material", icon="GREASEPENCIL", text="")
             row.operator("bim.unassign_material", icon="X", text="")
 
@@ -200,7 +202,9 @@ class BIM_PT_object_material(Panel):
         row.prop(self.props, "profile_classes", text="")
         if self.props.profile_classes == "IfcParameterizedProfileDef":
             row.prop(self.props, "parameterized_profile_classes", text="")
-            op = row.operator("bim.assign_parameterized_profile", icon="GREASEPENCIL" if item["Profile"] else "ADD", text="")
+            op = row.operator(
+                "bim.assign_parameterized_profile", icon="GREASEPENCIL" if item["Profile"] else "ADD", text=""
+            )
             op.ifc_class = self.props.parameterized_profile_classes
             op.material_profile = item["id"]
         else:

src/ifcopenshell-python/ifcopenshell/api/material/add_material.py

@@ -1,6 +1,3 @@
-import ifcopenshell
-
-
 class Usecase:
     def __init__(self, file, **settings):
         self.file = file

src/ifcopenshell-python/ifcopenshell/api/material/copy_material.py

@@ -0,0 +1,30 @@
+import ifcopenshell
+import ifcopenshell.util.element
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"material": None, "element": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        ifcopenshell.api.run("material.unassign_material", self.file, product=self.settings["element"])
+        if self.settings["material"].is_a("IfcMaterial"):
+            ifcopenshell.api.run(
+                "material.assign_material",
+                self.file,
+                product=self.settings["element"],
+                type="IfcMaterial",
+                material=self.settings["material"],
+            )
+        # No other material type can be copied right now.
+        # 1. Material lists and constituents may have shape aspects and I
+        # haven't implemented it yet.
+        # 2. Material layer and profile sets implicitly define parametric
+        # geometry and we have no way of guaranteeing that this constraint is
+        # satisfied.
+        # 3. Material set usages follow an unofficial constraint that all
+        # instances must have a usage of their type's material set. We cannot
+        # guarantee that constraint.